TGF-β1-induced Fascin1 promotes cell invasion and metastasis of human 786-0 renal carcinoma cells

Fascin actin-bundling protein 1 in human cancer: promising biomarker or therapeutic target?

Fascin actin-bundling protein 1 (FSCN1) is a highly conserved actin-bundling protein that cross links F-actin microfilaments into tight, parallel bundles. Elevated FSCN1 levels have been reported in many types of human cancers and have been correlated with aggressive clinical progression, poor prognosis, and survival outcomes. The overexpression of FSCN1 in cancer cells has been associated with tumor growth, migration, invasion, and metastasis. Currently, FSCN1 is recognized as a candidate biomarker for multiple cancer types and as a potential therapeutic target. The aim of this study was to provide a brief overview of the FSCN1 gene and protein structure and elucidate on its actin-bundling activity and physiological functions. The main focus was on the role of FSCN1 and its upregulatory mechanisms and significance in cancer cells. Up-to-date studies on FSCN1 as a novel biomarker and therapeutic target for human cancers are reviewed. It is shown that FSCN1 is an unusual biomarker and a potential therapeutic target for cancer.

Overexpression of PKMYT1 Facilitates Tumor Development and Is Correlated with Poor Prognosis in Clear Cell Renal Cell Carcinoma

BACKGROUND Protein kinase membrane-associated tyrosine/threonine (PKMYT1) has been found in many tumors, but its association with clear cell renal cell carcinoma (ccRCC) remains unclear. MATERIAL AND METHODS PKMYT1 expression in ccRCC was examined in the Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), and Tumor Immune Estimation Resource databases. The correlation between PKMYT1 expression and clinicopathological parameters was explored via the chi-square test. Receiver operating characteristic curves were used to estimate the diagnostic performance of PKMYT1. Kaplan-Meier curves, a Cox model, nomogram, time-dependent receiver operating characteristic curves, and decision curve analysis (DCA) were used to evaluate the prognostic value and clinical utility of PKMYT1. Genes coexpressed with PKMYT1 in ccRCC were identified based on TCGA, the gene expression profiling interactive, and cBioPortal. Gene Set Enrichment Analysis revealed biological pathways associated with PKMYT1 in ccRCC. RESULTS Weighted gene coexpression network analysis identified PKMYT1 as one of the genes most significantly correlated with progression of histological grade. PKMYT1 was significantly upregulated in ccRCC compared with normal tissue (P<0.001), with a trend toward differentiating between individuals with ccRCC and those who were healthy (area under the curve=0.942). High PKMYT1 expression was correlated with unsatisfactory survival (hazard ratio=1.67, P=0.001), indicating that it is a risk factor for ccRCC. A nomogram incorporating PKMYT1 level was created and showed a clinical net benefit. PKMYT1 was strongly positively correlated with the anti-silencing function of 1B histone chaperone (ASF1B) gene in ccRCC. CONCLUSIONS PKMYT1 is upregulated in ccRCC and its presence indicates poor prognosis, making it a potential therapeutic target for ccRCC.

Transforming growth factor-β1 enhances proliferative and metastatic potential by up-regulating lymphoid enhancer-binding factor 1/integrin αMβ2 in human renal cell carcinoma

Renal cell carcinoma (RCC) is a kind of malignant tumor with high recurrence, and it is urgent to find molecular markers for diagnosis and prognosis of RCC. Our study investigated the expression and function of integrin αMβ2 in RCC cells, aiming to understand the role of integrin αMβ2 in RCC and develop new therapeutic target for RCC. Overexpression and knockdown of lymphoid enhancer-binding factor 1 (LEF1) were performed using vector containing full-length cDNA and via siRNA technology, respectively. The expressions of mRNA and protein were detected by RT-PCR and Western blot, respectively. Proliferation of RCC cell was analyzed using WST-1 assay, and metastasis of RCC cell was evaluated using the transwell system. Our results demonstrated that LEF1 and integrin αMβ2 were up-regulated in RCC cells via TGF-β1-dependent mechanism, and LEF1 together with β-catenin directly increased integrin αMβ2 level. On the other hand, TGF-β1-induced proliferation, migration and invasion were suppressed by function-blocking antibody against integrin αMβ2 in RCC cells. In addition, integrin αMβ2 is crucial for LEF1 mediated cell invasion by regulating MMP-2, MMP-9 and calpain-2 secretion in RCC cells. LEF1/integrin αMβ2 expression was regulated by TGF-β1, and LEF1/integrin αMβ2 was involved in TGF-β1's improvement effects on the proliferation and metastasis of RCC. Blocking integrin αMβ2 activity could be a therapeutic option for patients with advanced RCC.

TGF-β and microRNA Interplay in Genitourinary Cancers

Genitourinary cancers (GCs) include a large group of different types of tumors localizing to the kidney, bladder, prostate, testis, and penis. Despite highly divergent molecular patterns, most GCs share commonly disturbed signaling pathways that involve the activity of TGF-β (transforming growth factor beta). TGF-β is a pleiotropic cytokine that regulates key cancer-related molecular and cellular processes, including proliferation, migration, invasion, apoptosis, and chemoresistance. The understanding of the mechanisms of TGF-β actions in cancer is hindered by the "TGF-β paradox" in which early stages of cancerogenic process are suppressed by TGF-β while advanced stages are stimulated by its activity. A growing body of evidence suggests that these paradoxical TGF-β actions could result from the interplay with microRNAs: Short, non-coding RNAs that regulate gene expression by binding to target transcripts and inducing mRNA degradation or inhibition of translation. Here, we discuss the current knowledge of TGF-β signaling in GCs. Importantly, TGF-β signaling and microRNA-mediated regulation of gene expression often act in complicated feedback circuits that involve other crucial regulators of cancer progression (e.g., androgen receptor). Furthermore, recently published in vitro and in vivo studies clearly indicate that the interplay between microRNAs and the TGF-β signaling pathway offers new potential treatment options for GC patients.

Effect of EH domain containing protein 2 on the biological behavior of clear cell renal cell carcinoma

To investigate the effects of EH domain containing protein 2 (EHD2) on clear cell renal cell carcinoma (ccRCC) and provide new insights for the clinical treatment of rental cancer. Forty patients (26 males and 14 females, 62.4 ± 5.7 years old) with ccRCC were selected from January 2015 to December 2016 to serve as research subjects in this study. The EHD2 protein expression in the tumor tissues and adjacent healthy tissues of ccRCC patients were detected by Western Blot assay. The cells of ccRCC cell lines RLC-310 and 786-O were divided into normal control group (control), no-load control group (pLV), EHD2 overexpression group (pLV-EHD2), and EHD2 interference group (pLV-siEHD2). The expression levels of EHD2 protein in each group of cells were detected by western blot. The cell proliferation was detected by Cell Counting Kit-8 (CCK-8) assay. Wound healing assay was performed to check the cell migration ability. Transwell invasion assay was used to detect the cell invasion ability. Cell apoptosis was detected by flow cytometry. The expression level of EHD2 was significantly increased in pLV-EHD2 group and decreased in pLV-siEHD2 group compared with control group and pLV-siEHD2 group, indicating the successfully established EHD2 overexpression cell line and EHD2 RNA interference cell line. EHD2 overexpression enhanced the proliferation, invasion, and migration but inhibited the apoptosis of ccRCC cells, while EHD2 interference showed opposite functions. EHD2 interference can inhibit the development of ccRCC by inhibiting the proliferation, invasion, and migration, and EHD2 can potentially serve as a molecular target for the clinical treatment of ccRCC.

SMAD proteins directly suppress PAX2 transcription downstream of transforming growth factor-beta 1 (TGF-β1) signalling in renal cell carcinoma

Canonical TGF-β1 signalling promotes tumor progression by facilitating invasion and metastasis, whereby release of TGF-β1, by (for example) infiltrating immune cells, induces epithelial to mesenchymal transition (EMT). PAX2, a member of the Paired box family of transcriptional regulators, is normally expressed during embryonic development, including in the kidney, where it promotes mesenchymal to epithelial transition (MET). PAX2 expression is silenced in many normal adult tissues. However, in contrast, PAX2 is expressed in several cancer types, including kidney, prostate, breast, and ovarian cancer. While multiple studies have implicated TGF-β superfamily members in modulating expression of Pax genes during embryonic development, few have investigated direct regulation of Pax gene expression by TGF-β1. Here we have investigated direct regulation of PAX2 expression by TGF-β1 in clear cell renal cell carcinoma (CC-RCC) cell lines. Treatment of PAX2-expressing 786-O and A498 CC-RCC cell lines with TGF-β1 resulted in inhibition of endogenous PAX2 mRNA and protein expression, as well as expression from transiently transfected PAX2 promoter constructs; this inhibition was abolished in the presence of expression of the inhibitory SMAD, SMAD7. Using ChIP-PCR we showed TGF-β1 treatment induced SMAD3 protein phosphorylation in 786-O cells, and direct SMAD3 binding to the human PAX2 promoter, which was inhibited by SMAD7 over-expression. Overall, these data suggest that canonical TGF-β signalling suppresses PAX2 transcription in CC-RCC cells due to the direct binding of SMAD proteins to the PAX2 promoter. These studies improve our understanding of tumor progression and epithelial to mesenchyme transition (EMT) in CC-RCC and in other PAX2-expressing cancer types.

FSCN1 predicts survival and is regulated by a PI3K-dependent mechanism in renal cell carcinoma

While overexpression of FSCN1 is reported in several cancers, the prognostic significance of FSCN1 in renal cell carcinoma (RCC) and the molecular mechanisms involved remain largely unclear. We retrospectively enrolled 194 patients with non-metastatic clear-cell RCC undergoing nephrectomy in our center between 2008 and 2011. FSCN1 expression was assessed by immunohistochemical staining and its association with clinicopathologic features and survival were evaluated. Functional effects of a modulated FSCN1 expression were analyzed with regard to invasion in RCC cell lines and metastasis in vivo. Here, we reported that FSCN1 was up-regulated in RCC tissues compared to non-tumor tissues, and associated with poor overall survival and recurrence-free survival. Its expression was not associated with age, tumor size, and clinical TNM stage. The incorporation of FSCN1 into the T stage and histologic grade would help to refine individual risk stratification. Preclinical studies using multiple RCC cells and orthotopic xenografts mice model indicated that FSCN1 could promote RCC cell invasion in vitro, and metastasis in vivo. Mechanistically, overexpression of FSCN1 led to an up-regulation of MMP9 and N-Cadherin. Notably, treating RCC cells with PI3 K/AKT inhibitors or knockdown GSK-3β decreased the expression of FSCN1, and then attenuated RCC invasion. Together, our results demonstrate that FSCN as an oncogene is a potential novel prognostic biomarker for RCC patients after nephrectomy, and can promote RCC metastasis.

MiR-429 is linked to metastasis and poor prognosis in renal cell carcinoma by affecting epithelial-mesenchymal transition

MicroRNAs (miRNAs) have been proven to be important oncogenes and tumor suppressors in wide range of cancers, including renal cell carcinoma (RCC). In our study, we evaluated miRNA-429 as potential diagnostic/prognostic biomarker in 172 clear cell RCC patients and as a potential regulator of epithelial-mesenchymal transition (EMT) in vitro. We demonstrated that miR-429 is down-regulated in tumor tissue samples (P < 0.0001) and is significantly associated with cancer metastasis (P < 0.0001), shorter disease-free (P = 0.0105), and overall survival (P = 0.0020). In addition, ectopic expression of miR-429 in 786-0 RCC cells followed by TGF-β treatment led to increase in the levels of E-cadherin expression (P < 0.0001) and suppression of cellular migration (P < 0.0001) in comparison to TGF-β-treated controls. Taken together, our findings suggest that miR-429 may serve as promising diagnostic and prognostic biomarker in RCC patients. We further suggest that miR-429 has a capacity to inhibit loss of E-cadherin in RCC cells undergoing EMT and consequently attenuate their motility.